Initial lookbook implementation

Pinterest-style visual bookmarking app with:
- URL metadata extraction (OG/Twitter meta, oEmbed fallback)
- Image caching in Postgres with 480px thumbnails
- Multi-tag filtering with Ctrl/Cmd for OR mode
- Fuzzy tag suggestions and inline tag editing
- Browser console auth() with first-use password setup
- Brutalist UI with Commit Mono font and Pico CSS
- Light/dark mode via browser preference

vendor/golang.org/x/text/secure/precis/class.go

@@ -0,0 +1,36 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package precis
+
+import (
+	"unicode/utf8"
+)
+
+// TODO: Add contextual character rules from Appendix A of RFC5892.
+
+// A class is a set of characters that match certain derived properties. The
+// PRECIS framework defines two classes: The Freeform class and the Identifier
+// class. The freeform class should be used for profiles where expressiveness is
+// prioritized over safety such as nicknames or passwords. The identifier class
+// should be used for profiles where safety is the first priority such as
+// addressable network labels and usernames.
+type class struct {
+	validFrom property
+}
+
+// Contains satisfies the runes.Set interface and returns whether the given rune
+// is a member of the class.
+func (c class) Contains(r rune) bool {
+	b := make([]byte, 4)
+	n := utf8.EncodeRune(b, r)
+
+	trieval, _ := dpTrie.lookup(b[:n])
+	return c.validFrom <= property(trieval)
+}
+
+var (
+	identifier = &class{validFrom: pValid}
+	freeform   = &class{validFrom: idDisOrFreePVal}
+)